"I can assure you the president's number one priority is the safety of the American people and our allies," Mnuchin said in an interview on ABC. "The president doesn't want to be in a nuclear war. And we will do everything we can to make sure that doesn't occur."

On how the U.S. should respond in the event of an H-bomb test in the Pacific, Mnuchin declined to comment.

"The president has said all the options are on the table," he said. "The president has lots of alternatives that have been presented to him, and he'll make decisions at the time."

On Thursday, Trump signed an executive order that authorized the Treasury Department to block foreign individuals and entities doing business with North Korea from accessing the U.S. financial system.

The order, Mnuchin said, allows him to issue the "most strong sanctions that have ever been done."

But there is room for even more sanctions, Sen. Cory Gardner (R-CO) said in a separate interview on CBS.

"We have a long ways to go to continue to ratchet up the economic and diplomatic pressure on North Korea and the enablers of North Korea," he said, noting the country is only the fourth or fifth most sanctioned nation in the world.

The senator, who authored a North Korea sanctions bill that was signed into law last year, emphasized the ultimate goal must be the peaceful denuclearization of the regime because anything short of that will lead to continued threats against the homeland and proliferation in the region.

"I've already been approached by members of (South) Korea's National Assembly to put in place tactical nuclear weapons by the United States on the South Korean peninsula," he said.

South Korea's conservative opposition parties are seeking the weapons' redeployment to counter the threat posed by North Korea's repeated missile launches and sixth nuclear test earlier this month.

The liberal administration of President Moon Jae-in has dismissed the idea, saying it would go against the principle of denuclearization.

The U.S. removed all tactical nukes from the peninsula in the early 1990's.